docs: def head(self, n=6):
          """
          Returns first n values of your column as a DataFrame. This is executing:
              SELECT
                  <name_of_the_column>
              FROM
                  <name_of_the_table>
              LIMIT <n>
  
          Parameters
          ----------
          n: int
              number of rows to return
  
          Examples
          --------
          >>> from db import DemoDB
          >>> db = DemoDB()
          >>> db.tables.Customer.City.head()
          0    Sao Jose dos Campos
          1              Stuttgart
          2               Montreal
          3                   Oslo
          4                 Prague
          5                 Prague
          Name: City, dtype: object
          >>> db.tables.Customer.City.head(2)
          0    Sao Jose dos Campos
          1              Stuttgart
          Name: City, dtype: object
          """
          q = self._query_templates['column']['head'].format(column=self.name, schema=self.schema,
                                                             table=self.table, n=n)
          return pd.read_sql(q, self._con)[self.name]